Forgetfulness: when is it normal and when is it not?

A name that will not come. Keys that have gone missing. After 60, that is usually just forgetfulness, and not the start of dementia. There are signals that do deserve attention, though, and causes that can be treated well.

The difference is not in how often you forget. It is in what you forget.

Is forgetfulness always dementia?

No, and that is the most important thing you can read here. Your brain works a little more slowly with age, and retrieving names and words takes longer. That is not a disease. It becomes more concerning only when the forgetting starts getting in the way of daily life.

The Hersenstichting, the Dutch brain foundation, draws the same line. Forgetting where you put your glasses is normal. Forgetting what glasses are for is not.

What is the difference between normal and concerning?

With ordinary forgetfulness you know something is missing, and it usually comes back to you later. In a more concerning picture the memory disappears entirely, you lose the thread in familiar surroundings, and other people often notice before you do. That last one is a meaningful difference.

If you mostly recognise the right-hand column, make an appointment. Not out of fear, but because some of the causes can be treated.

Which causes of forgetfulness can be treated?

More than people think. A vitamin B12 deficiency, an underactive thyroid, anaemia, depression, lack of sleep, too much alcohol and certain medicines can all affect your memory. These causes are not often the explanation, but they are worth ruling out (Muangpaisan et al., 2012).

For B12 the link is best studied. A systematic review of prospective cohort studies found an association between low B12 status and cognitive decline, though the direction of that link remains hard to pin down (Clarke et al., 2012).

What I find most hopeful here: this is exactly the kind of cause you can do something about. Which values your GP checks for it is set out in tired and forgetful. We wrote a separate piece on B12 after 60.

When should you see your GP?

See your GP if your memory noticeably declines within months, if you lose the thread in familiar situations, or if your partner or children are worried. An appointment is also sensible when forgetfulness comes with low mood, dizziness or fatigue. Your GP will then look further.

Do not wait for it to pass on its own, and do not go hunting for a diagnosis online.

What your GP actually does at such an appointment, and which tests are involved, is covered in is there a test for dementia.

An example from practice

An example helps here. Picture a woman of 68. In recent months she has forgotten appointments more often, she is tired, and she has little appetite for leaving the house. Her GP requests blood work. Her vitamin B12 comes back at 130 pmol/l, well below the lower limit, and her haemoglobin is slightly low.

That does not explain everything. It does explain something, and it can be treated.

Had nobody looked at her blood, that B12 would never have surfaced. This is why these values sit on the GP's standard list.

Can you prevent forgetfulness?

Partly. The same factors that shape your dementia risk also shape your memory in the shorter term: your blood pressure, your blood sugar, your cholesterol, exercise, sleep, alcohol and your hearing. The Lancet Commission brought those factors together in 2024 (Livingston et al., 2024).

Which of those fourteen factors you can influence, and which two of them are visible in your blood, is set out in our overview on preventing dementia.

If you want the treatable causes checked, a vitamin and iron panel is a logical starting point. If your memory is genuinely declining, see your GP first.

References

1. Muangpaisan W, et al. (2012). Prevalence of potentially reversible conditions in dementia and mild cognitive impairment in a geriatric clinic. Geriatr Gerontol Int. PMID 21794050.
2. Clarke R, et al. (2012). Vitamin B12 status, cognitive decline and dementia: a systematic review of prospective cohort studies. Br J Nutr. PMID 23084026.
3. Livingston G, et al. (2024). Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. The Lancet. PMID 39096926.
4. Hersenstichting. Memory complaints and forgetfulness. hersenstichting.nl.
5. RIVM. Figures on dementia in the Netherlands. rivm.nl.

Would you like the treatable causes of forgetfulness checked at a calm moment, without first booking an appointment with your GP? At Levenswijs Health you can. Every result is reviewed by a doctor registered in the Dutch BIG register. A blood test does not provide a diagnosis and cannot detect dementia. For treatment decisions, always discuss your results with your GP.